Think of your house as a system with pathways in and out. Think of all the ways that ‘stuff’ comes into your house: you bring it home from the store, the mailman delivers it, it comes out of your pipes. On this blog we usually talk about one of the main exit pathways – the trashcan. An exit we haven’t written as much about is the sewer.
Think of everything you get rid of down the drain: dirty dish water, laundry water (along with detergent, bleach, ‘Shout,’ Oxyclean, and whatever else you can get your hands on to clean Phil’s stain-magnet clothes…), shower water (along with your personal care products – soap, shampoo, make-up, residue from that must-have hair gel to give your hair the extra spike it needs), food, if you have a disposal, and toilet water (and anything that comes out of you).
Now think of all that water zooming out through your pipes, coasting towards a treatment plant, joining with your annoying neighbor’s toilet water, and then with the mayor’s dirty laundry water, and then with wastewater from a local brewery, and maybe from a car mechanic’s shop… where do you think this all ends up? And what’s the impact of all these things in our wastewater streams?
We met with Laura Orlando, from RILES, who is very concerned about all the shit in our water [heh heh heh]. While our wastewater treatment systems are equipped to deal with things like pH, oil and grease, and fecal coliform bacteria, they can do very little with the heavy metals, pharmaceuticals, hormones, and industrial chemicals also present. Much of these ends up in the sludge – the semi-solid goo left after wastewater treatment.
Laura pointed out that one of the main uses or disposal methods (take your pick) of sewage sludge is spreading it on farmland as a soil amendment (50% of sludge in the US ends up spread on land). While ‘sludging’ may be pitched as an ecologically sensitive way of recycling nutrients, there are many who have their concerns about the long-term environmental and human health impacts of this practice (remember our story about Merco in Sierra Blanca, TX?).
RILES produces Sludge News, a resource devoted to debunking the myth that sludge is safe. The website keeps an up-to-date list of studies and articles documenting human and environmental health impacts of sludging. Numerous studies have found things like flame retardants and antibiotics in sludge applied to farmland; these in turn may be working their way into our food systems. Laura pointed out that land application is the cheapest way to dispose of sludge, plus it helps sludge haulers make a nice profit.
So what’s the solution? While many people push for new and improved water treatment technology (an !!!expensive!!! solution that could take decades to implement) RILES advocates prevention: 1) stop promoting the land application of sludge as safe (RILES holds that there are no scientific grounds for this claim), 2) stop any land application of sludge (in the interim, RILES argues that landfills may be the safest storage option for sludge), and 3) stop creating more sludge. The last part – halting the creation of more sludge – requires a re-envisioning of our sewer systems. This could include decentralizing systems so they don’t rely on clean potable water for waste transport (thus contaminating more water!), and preventing the mixing of diverse waste streams (such as keeping industrial waste separate from household wastewater). If you think about it, our current sewer system is pretty crazy.